为什么chronounit.hours.between（）不起作用？

Question

我想知道两次当地约会之间的时间。我使用了下面的代码：

 LocalDate startDate =  LocalDate.of(2000, 4, 30);

    long noOfHours = startDate.until(LocalTime.now(), ChronoUnit.HOURS);
    
    System.out.println(noOfHours);

我有以下错误：

Exception in thread "main" java.time.DateTimeException: Unable to obtain LocalDate from TemporalAccessor: 13:44:53.095819600 of type java.time.LocalTime
    at java.base/java.time.LocalDate.from(LocalDate.java:397)
    at java.base/java.time.LocalDate.until(LocalDate.java:1645)
    at BirthDay.App.main(App.java:36)

Answer 1

正如异常所述：您需要一致的绑定值，localtime没有与localdate相比较的日/月/年组合

LocalDate startDate = LocalDate.of(2000, 4, 30);
long noOfHours = startDate.until(LocalTime.now(), ChronoUnit.HOURS);
// >> DateTimeException: Unable to obtain LocalDate from java.time.LocalTime

此外，还需要具有chronounit所需单位的组合，使用2个localdate不能使用hours，因为它们没有。

LocalDate startDate = LocalDate.of(2000, 4, 30);
long noOfHours = startDate.until(LocalDate.now(), ChronoUnit.HOURS);
// >> UnsupportedTemporalTypeException: Unsupported unit: Hours

使用LocalDateTime，使边界和单位时间一致

LocalDateTime startDate = LocalDateTime.of(2000, 4, 30, 0, 0, 0);
long noOfHours = startDate.until(LocalDateTime.now(), ChronoUnit.HOURS);
System.out.println(noOfHours); // 185793